Tim Karle, the park ranger at the Klondike Gold Rush National Historic Park, wonders whether today’s oil and gas boom in the Midwest will turn into yet another American stampede for precious resources. And he says this as someone who lived in Alaska four decades ago as his brother worked on the oil pipeline.

Karle said he saw his brother in all these people and that nothing that he did “was different than what the gold-rush workers did or what the folks today are doing in the Dakotas.” Karle, 63, said his brother worked nonstop for nine or 10 weeks with the pay being $1,400 a week for unskilled labor. “During the gold rush [in the late 1890s], newspapers advertised jobs that paid $11 to $14 a day. We’d laugh today, but that was a week’s salary in the Lower 48. Now you hear about truck drivers in North Dakota making all kinds of money.”

Money is all you hear about right now in the exploitation of oil and gas in America’s heartland, where the practice of hydraulic fracturing, known as “fracking,” has unleashed previously unreachable reserves. According to USA Today, per capita income in Williams County, N.D., an epicenter of the boom, is now $81,170, more than in Nantucket County in Massachusetts or Fairfield County in Connecticut, and just under Marin County in California.

According to the Census Bureau, Williams County’s main city of Williston was the fastest-growing small city in the nation between 2010 and 2011, adding nearly 9 percent more people, and the cities of Dickinson and Minot were fourth and eighth. Unemployment in Williams County is 0.8 percent and a story this week in the Bismarck Tribune said Williston, which has 20,500 permanent residents and 15,000 service workers, may add 38,000 people in the next four years.

“We’ve had oil here for 560 years and we’ve had booms and busts,” Williston Mayor Ward Koeser told the Fort Myers News-Press. “We never had anything as intense as we have now.”

Such intensity makes Karle and fellow ranger Ruth Kerr wonder what will happen when the new boom goes bust. Their gold rush museum is a classic testament to the possibilities. While cities like Seattle continued to thrive, many towns along the gold trail to the Yukon disappeared as fast as they rose up. “When you look at the photos with all the men camping in the pictures, it’s amazing to go to where the town of Dyea [Alaska] was,’’ Kerr said. “Thousands of people came through there. But all that’s really left is the old boards of a side of a building [and 59 residents]. Some towns just couldn’t compete.”

Kerr, 68, said the photographs of prospectors are also haunting reminders of what, for many, turned out to be a rush to oblivion. “It was really tragic,” she said. “The expressions in so many faces have so much sadness in them for what they are chasing and the families they left behind.”

While not casting any official judgment on the practice of fracking, Karle and Kerr both said that the rush is one more example of how environmental concerns have taken a back seat to America’s desire to drill now and ask questions later. There remain many unresolved questions about whether the process of breaking up rock deep under the earth with a high-pressure mix of water and chemicals puts groundwater at risk or releases toxins into the air.

“One thing you hardly ever hear about when we talk about booms of the past is how we really ripped up the environment,” Karle said. “Nobody talks about the mercury from gold mining and all the forests brought down for the pipeline. You hear a little more about it now, but it’s clearly not the main focus. We still believe that man can conquer nature.”

There may be riches in the Midwest, but history indicates that many men and women who are caught up in the fracking boom will eventually adopt the same sad faces as their predecessors. A few people may conquer nature. Many more may end up being conquered.